Programmed Synthesis of Freestanding Graphene Nanomembrane Arrays

Abstract

Freestanding graphene membranes are unique materials. The combination of atomically thin dimensions, remarkable mechanical robustness, and chemical stability, make porous and non-porous graphene membranes attractive for water purification and various sensing applications. Nanopores in graphene and other 2D materials have been identified as promising devices for next-generation DNA sequencing, based on readout of either transverse DNA base-gated current or through-pore ion current. While several ground breaking studies of graphene-based nanopores for DNA analysis have been reported, all methods reported to date require a physical transfer of the graphene from its source of production onto an aperture support. The transfer process is slow and often leads to tears in the graphene that render many devices useless for nanopore measurements. In this work, we report a novel scalable approach for site-directed fabrication of pinhole-free graphene nano-membranes. Our approach yields high quality few-layer graphene nano-membranes produced in less than a day using a few steps that do not involve transfer. We highlight the functionality of these graphene devices by measuring DNA translocation through electron-beam fabricated nanopores in such membranes.

Direct and Scalable Deposition of Atomically Thin Low-Noise MoS2 Membranes on Apertures

“…A custom-made silicon support is placed atop the Mo-boat, such that a series of SiN x membrane devices can be placed above the boat. Aperture-containing substrate devices were prepared using a previously described procedure: 26 A series of 5 × 5 mm 2 chips that contain freestanding 30–50 μm 2 membranes of 100 nm-thick freestanding SiN x were cleaned using hot piranha solution and dried with a gentle flow of nitrogen (N 2 ) gas. Next, positive electron beam resist was spun onto the membrane side of the chips, and a single 0.5–2 μm-diameter circular hole was (or pattern of holes were) written on each of the membranes using e-beam lithography (Hitachi S-4800, NPGS EBL software).…”

Role of Nanomaterials in the Treatment of Wastewater: A Review

“…The doping process of nanomaterial (zeolite, alumina, TiO 2 , etc.) into polymer ultra-filtration membranes show the formation of amplified membrane on surface of hydrophilicity and fouling resistance [118][119][120]. The antimicrobial material like silver metal particles are also doped with a polymer to produce polymeric membrane to prevent attachment of bacteria and inhibit biofilm production on surface of membrane [121,122].…”

Assembly and Self‐Assembly of Nanomembrane Materials—From 2D to 3D

“…In particular, free‐standing nanomembranes with a thickness of a few nanometers were predicted to possess a superior performance in the separation of materials, because they can allow a faster passage of the selected ions or molecules . As a step further, the ion transport characteristics in the graphene nanomembrane were investigated in detail . A similar approach was also used to measure DNA translocation by using graphene nanomembrane with electron‐beam fabricated nanopores .…”

“…As a step further, the ion transport characteristics in the graphene nanomembrane were investigated in detail . A similar approach was also used to measure DNA translocation by using graphene nanomembrane with electron‐beam fabricated nanopores . Due to their long mean‐free path, high Fermi velocity, and excellent charge dissociation ability, the 2D material nanomembranes found advantageous applications in photovoltaic devices.…”

“…[285] A similar approach was also used to measure DNA translocation by using graphene nanomembrane with electron-beam fabricated nanopores. [285] Due to their long mean-free path, high Fermi velocity, and excellent charge disso ciation ability, [281,286,287] the 2D material nanomembranes found advantageous applications in photovoltaic devices. The fabrication processes are compatible with Si planar process and solar cells with high efficiencies can be obtained.…”